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Bug 4604 - Divide by zero crash in voc_get_block()
Summary: Divide by zero crash in voc_get_block()
Status: RESOLVED FIXED
Alias: None
Product: SDL_mixer
Classification: Unclassified
Component: misc (show other bugs)
Version: unspecified
Hardware: All All
: P2 normal
Assignee: Ozkan Sezer
QA Contact: Sam Lantinga
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2019-04-21 08:07 UTC by Mark Terbeck
Modified: 2020-06-26 22:01 UTC (History)
1 user (show)

See Also:

Attachments
VOC file that triggers the bug. (4.06 KB, application/octet-stream)
2019-04-21 12:19 UTC, Mark Terbeck 		Details
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Description Mark Terbeck 2019-04-21 08:07:07 UTC 
The crash happens within the a extended information block (case VOC_EXTENDED) handling, due to the fact that number of channels is never set for mono samples. So when the sample rate is calculated the divisor is 0.

To fix this simply add a else clause - which sets the number of channels to 1 - to the if() which sets the number of channels to 2 for stereo.

This bug is present in SDL_mixer 1.2.12, SDL_mixer 2.0.4 and SDL_sound.
Comment 1 Mark Terbeck 2019-04-21 12:19:24 UTC 
Created attachment 3761 [details]
VOC file that triggers the bug.
Comment 2 Ozkan Sezer 2020-06-26 21:52:29 UTC 
Should be fixed in both SDL_mixer-1.2 and SDL2_mixer:
http://hg.libsdl.org/SDL_mixer/rev/33b9d022472d
http://hg.libsdl.org/SDL_mixer/rev/037c22bc945d
Comment 3 Ozkan Sezer 2020-06-26 22:01:07 UTC 
SDL_sound version of fixes are in my fork of SDL_sound at github:
https://github.com/sezero/SDL_sound/commit/a343b5ac38cbace0c129c51023f6a9a4c464eb30
https://github.com/sezero/SDL_sound/commit/815ad2191a5b67795735000af2177446f06bbb60

(icculus doesn't seem to work on SDL_sound for quite some time..)